JP2011-131871A discloses a vehicle air-conditioning device that is mounted on a hybrid vehicle and that circulates engine coolant water between a heater core and an engine to heat air that has passed through an evaporator by performing heat exchange between the engine coolant water and the air. This vehicle air-conditioning device includes a heat-absorbing side heat exchanger that is provided at the downstream side of the heater core, a heat-releasing side heat exchanger that is provided at the upstream side of the heater core, and a Peltier device that is provided between the heat-absorbing side heat exchanger and the heat-releasing side heat exchanger. With this device, when the engine is stopped, temperature of the engine coolant water that flows into the heater core is prevented from being decreased by transferring heat via the Peltier device from the engine coolant water flowing on the downstream side of the heater core to the engine coolant water flowing on the upstream side of the heater core.